=over

=item truncate FILEHANDLE,LENGTH
X<truncate>

=item truncate EXPR,LENGTH

Truncates the file opened on FILEHANDLE, or named by EXPR, to the
specified length.  Raises an exception if truncate isn't implemented
on your system.  Returns true if successful, L<C<undef>|/undef EXPR> on
error.

The behavior is undefined if LENGTH is greater than the length of the
file.

The position in the file of FILEHANDLE is left unchanged.  You may want to
call L<seek|/"seek FILEHANDLE,POSITION,WHENCE"> before writing to the
file.

Portability issues: L<perlport/truncate>.

=back